POPULATION DYNAMICS OF THE BIGEYE CROAKER MICROPOGONIAS MEGALOPS IN THE NORTHERN GULF OF CALIFORNIA

Knowledge of biomass and demographic aspects is important in fish stock assessments. These aspects were analyzed on Micropogonias megalops in the Gulf of California, Mexico, using biological data from catches in 2010-12. Individual growth was estimated following a multi-model approach. Logistic models were used for first maturity and fishing selectivity, and natural mortality by means of empirical equations and biomass by the Pennington estimation.The results showed that the von Bertalanffy model best described growth for combined data (w(i) = 72.86 %), females (w(i) = 67.82 %) and males (w(i) = 69.42 %), but they showed sexual dimorphism on the species. First maturity was at 357.8 mm, fishing selectivity 323.35 and 366.35 mm for industrial and artisanal fleet, respectively, and average natural mortality of 0.51. Mean biomass was 14 412.9 tons contrasting the officially reported catch that represented only 8.7% of estimated biomass, showing evidence that M. megalops is still an underexploited resource.